Method for treating polymeric fibers

ABSTRACT

Ester lubricant compositions are provided which provide a good balance of lubricity and emulsifiability. The esters are derived from polyoxyalkylene glycols with a dibasic acid mixture consisting of dimer acids and short-chain dibasic acids. The emulsions and clear, homogeneous lubricant solutions provide excellent spin finishes for fibers such as polyamides and polyesters.

This is a division of U.S. application Ser. No. 260,516 filed June 7,1972, now U.S. Pat. No. 3,850,682, which was a continuation-in-part ofU.S. Application Ser. No. 223,752 filed Feb. 4, 1972, now U.S. Pat. No.3,769,215.

BACKGROUND OF THE INVENTION

Numerous synthetic lubricants including ether compounds, esters andpolyesters, silicones and hydrocarbon polymers have been proposed toovercome the problems associated with the use of the natural oils andsome of these are useful in aqueous systems. Many of the syntheticlubricants, however, are not readily emulsifiable with water and if anemulsion can be formed, with or without the use of additional additives,most of these emulsions begin to separate after a very short time.

Synthetic lubricants derived from dimer acids such as obtained by thedimerization of oleic acid, linoleic acid or the like have beendescribed in U.S. Pat. Nos. 2,767,144 and 3,233,635. While extremelyeffective lubricants for a variety of applications such as metal workingand spin finishing of fibers can be obtained through the use of dimeracids, the compatibility of the dimer-based lubricant with water isgenerally very poor. A dimer-based synthetic polyester lubricant havingincrased hydrophilic character and useful in aqueous systems isdisclosed in U.S. Pat. No. 3,492,232. The polyester is derived from thereaction of 0.8 to 2.0 mols, and more preferably 1.0 to 1.5 mols,polyoxyalkylene glycol having a degree of polymerization of 4 to 200 and1 mol of a dimer of C₁₆ to C₂₆ fatty acid. While the compositions of theU.S. Pat. No. 3,492,232 present a significant advance in the technologyof dimer-based lubricants they are not without certain disadvantages.The resulting aqueous emulsions are relatively unstable and undergopartial phase separation within a very short period. Furthermore, manyof the polyesters cannot be satisfactorily emulsified without the use ofadditional emulsifying agents of the cationic and nonionic types.Employing additional emulsifier increases the cost of the lubricantcomposition in addition to adding another process variable and istherefore undesirable. The stability of the emulsions can be improvedthrough the use of higher molecular weight polyoxyalkylene glycols withthe dimer, but while the use of these high molecular weightpolyoxyalkylene glycols improves the physical characteristics of theemulsion it severely reduces the lubricating efficiency of thecomposition since the weight percent dimer acid incorporated therein isproportionately decreased.

It would be highly advantageous to have dimer acid-derived syntheticlubricants which are readily emulsifiable with water. It would beespecially advantageous if stable emulsions could be formed without theuse of external emulsifying aids and simply by moderately agitating thesynthetic lubricant with cold tap water. Additional benefit would bederived if synthetic lubricants employing low molecular weightpolyoxyalkylene glycols with dimer acid could be prepared so that a highweight percent dimer acid could be obtained; if these lubricants werereadily emulsifiable without the use of external emulsifying agents; andif the resulting emulsions were stable.

SUMMARY OF THE INVENTION

We have now discovered that improved ester lubricant compositionsderived from dimer acid and polyoxyalkylene glycols are obtained byincorporating therein an amount of short-chain dibasic acid. The estermixtures of this invention are more readily emulsifiable with water thanpolyesters derived from polyoxyalkylene glycol and dimer acid alone.Stable emulsions are obtained with the lubricant compositions of thisinvention without the use of external emulsifying aids. Quiteunexpectedly it has been found that the incorporation of the short-chaindibasic acid permits the use of low molecular weight polyoxyalkyleneglycols with the dimer acid and that the resulting mixed estercompositions, in addition to having increased lubricity as a result ofthe high weight percent dimer acid present, also have superioremulsification properties. This invention provides synthetic esterlubricants which have a good balance of emulsification and lubricationproperties. A further advantage and completely unexpected result is thediscovery that clear, homogeneous lubricant solutions can be preparedwhen the molar ratio of the polyoxyalkylene glycol, dimer acid andshort-chain dibasic acid is within certain defined limits.

The ester lubricants of the present invention are obtained by thecondensation reaction of polyoxyalkylene glycols having molecularweights ranging from 300 to 4000 and more preferably in the range 400 to1000, a dimer acid containing from about 32 to 54 carbon atoms and ashort-chain dibasic acid containing from 2 to 12 carbon atoms and morepreferably from about 6 to 10 carbon atoms. The molar ratio of dibasicacids (dimer acid plus short-chain dibasic acid) to polyoxyalkyleneglycol will be 1:1.5 - 2.1. The dimer acid will constitute from about 95to 5 mol percent of the total dibasic acid while the short-chain dibasicacid will range from about 5 to 95 mol percent. Excellent results areobtained when about 90 to 20 mol percent of the total dibasic acid isshort-chain dibasic acid. To obtain water-soluble ester lubricants about7.5 to about 20% by weight short-chain dibasic acid, based on theoverall ester composition, is employed. The water-soluble estersproducts have acid values of about 15 or below. The concentration of theester in aqueous emulsions or solutions useful as lubricants willgenerally range from about 0.1 to 25% by weight of the lubricantcomposition.

DETAILED DESCRIPTION

The ester lubricants of this invention are condensation products ofpolyoxyalkylene glycols with a mixture of dibasic acids and short-chaindibasic acids. These ester compositions are useful as lubricants and arereadily emulsifiable with water without the addition of externalemulsifying agents.

To obtain the lubricant esters of this invention, a polyoxyalkyleneglycol having a molecular weight from about 300 to about 4000, and morepreferably from 400 to 1000, is employed. The recurring alkylene groupsmay contain 2 to 4 carbon atoms and useful polyoxyalkylene glycolshaving varying degrees of polymerization include: polyethylene glycols,polypropylene glycols, polybutylene glycols, poly(ethylenepropylene)glycols and the like. Polyethylene glycols having molecular weights from400 to about 1000 are especially useful and are available fromcommercial suppliers under the trade designations "Carbowax" and"Polyox" or they may be synthesized in the conventional manner. Themolecular weights recited above indicate the average molecular weight ofthe polyoxyalkylene glycol and it is understood that these compositionsare mixtures of polyoxyalkylene glycols having widely divergentmolecular weights. Polyoxyalkylene glycols having molecular weights lessthan about 300 or greater than about 4000 should not, however, bepresent in significant amounts.

Condensed with the polyoxyalkylene glycol is a mixture of dibasic acidsconsisting of dimer acid and short-chain dibasic acid. The molar ratioof the dibasic acids, including both the dimer acid and the short-chaindibasic acid, to the polyoxyalkylene glycol will range from about1:1.5-2.1 with exceptional results being obtained when the molar ratiois 1:1.75-2.0. The proportion of dimer and short-chain dibasic acids maybe widely varied.

Useful dimer acids for the compositions of this invention contain fromabout 32 to 54 carbon atoms. The dibasic acids may be obtained byprocesses known to the art, however, they are most frequently obtainedby the polymerization of monocarboxylic acids containing ethyleneicunsaturation. The monocarboxylic unsaturated acids generally containfrom about 16 to 26 carbon atoms and include, for example, oleic acid,linoleic acid, eleostearic acid and similar singly or doubly unsaturatedacids. To obtain the preferred dimer acids 2 mols of the unsaturatedmonocarboxylic acid are reacted, i.e., dimerized. If the resulting dimeracid contains ethyleneic unsaturation it may be beneficial tohydrogenate it to obtain the saturated material prior to reaction withthe polyoxyalkylene glycol. Mixtures of dimer acids may be employed.Trimer and tetramer acids may also be present with the dimer acid and donot adversely affect the lubricant properties of the resulting estercompositions so long as about 50% by weight of the mixture arepolymerized acids. Commercially available compositions sold under thetrademark "Empol", mixtures of polymerized fatty acids with dimer acidas the major constituent, may be advantageously employed. Especiallyuseful are mixed acid products which will contain 75 weight percent ormore dimer acid with the remainder being unpolymerized fatty acids ormore highly polymerized acids such as trimer acids.

The short-chain dibasic acids contain from 2 to about 12 carbon atoms.Short-chain dibasic acids containing 6-10 carbon atoms are especiallypreferred for the present invention. Typical short-chain dibasic acidsinclude oxalic acid, malonic acid, succinic acid, glutaric acid, adipicacid, azelaic acid, sebacic acid, dodecanedioic acid and the like.Mixtures of one or more shortchain dibasic acids may be used.

The dibasic acid mixture consists of about 95 to 5 mol percent dimeracids with about 5 to 95 mol percent of one or more short-chain dibasicacids. Preferred ester lubricant compositions contain from about 80 to10 mol percent short-chain dibasic acid and from 90 to 20 mol percent ofthe dimer.

The condensation of the polyoxyalkylene glycol with the dimer andshort-chain dibasic acids is conducted employing conventionalesterification techniques, that is, by heating the reaction mixture withor without a catalyst at a temperature from about 100° to 300°C whileremoving the water of reaction. The reactions are most generallyconducted over the temperature range 175° to 250°C. It is not necessarythat a catalyst be employed for the esterification reaction, however,conventional acid catalysts such as sulfuric acid, alkyl and arylsulfonic acids such as p-toluene sulfonic acid, phosphorous acids or thelike may be employed. The reaction may be carried out in a diluent whichis inert to the reaction conditions employed and which, preferably, willform an azeotrope with water to facilitate the removal of the water ofreaction. The amount of reactants employed is in accordance with themolar ratios set forth above. For preparation of suitable esterlubricants it is undesirable for the esterification reaction to be lessthan about 70% complete, that is, 70% or more of the carboxyl groupsshould be reacted. The reaction is more generally continued toapproximately 85% completion. This may be determined by measurement ofthe acid value or hydroxyl value or by measuring the amount of waterevolved. For the preparation of certain preferred ester lubricants whichare water-soluble it is preferred that the reaction be continued untilit is 90% complete or even higher or, in terms of acid value, thereaction mixture has an acid value of about 15 or below.

As an alternative procedure for the preparation of the present esterlubricants, the dimer and short-chain dibasic acid may be reacted in thepresence of ethylene oxide. In this way the polyoxyethylene glycol wouldbe prepared in situ. Suitable catalysts and diluents could be added. Itis generally found, however, that more uniform control of molecularweight of the products is obtained when the polyoxyethylene glycol isseparately prepared.

Small amounts of other compounds capable of entering into the reactionmay also be included with the polyoxyalkylene glycol, dimer andshortchain dibasic acid and are within the scope of the presentinvention. Aromatic dibasic acids, diols and polyols, diamines andpolyamines may be employed in amounts which do not detract from theemulsification and lubrication properties to modify the resultinglubricant composition. For example, the use of diamines, such asdimethylaminopropylamine, may be desirable to enhance the anticorrosionproperties of the ester if it is to be used as a metalworking lubricant.The amount of these materials will not exceed about 10% and morepreferably 5% by weight of the overall ester composition.

The esters of the present invention provide a convenient means to obtaina good balance of lubrication and emulsification properties which wasnot previously possible when polyoxyalkylene glycols were simply reactedwith dimer acids without the addition of short-chain dibasic acids. Toachieve good lubrication properties with the prior art polyesters wouldrequire that the emulsification properties be compromised. Even ifadditional external emulsifying aids were added, the resulting emulsionswere not always completely satisfactory and in most instances they wouldbegin to separate after a very short time. Acceptable emulsions can beproduced employing the teachings of the prior art if the amount of dimeracid is diminished, however, this results in a marked decrease in thelubrication properties. For example, a polyester prepared by thecondensation of dimer acid with a polyethylene glycol of molecularweight 2000 or greater in accordance with prior art procedure would forman acceptable emulsion, but the lubrication properties would be inferiorand unacceptable for most applications. If, in accordance with the priorart procedure, a polyester was formed from a dimer acid and apolyethylene glycol of low molecular weight about 400, the lubricationproperties of the polyester would be greatly enhanced but the materialwould not emulsify readily or the emulsion, if formed, would not bestable.

In accordance with the present invention we have prepared mixed esterlubricants which are, at the same time, readily emulsifiable andexcellent lubricants. This is accomplished by replacing a portion of thedimer acid with a short-chain dibasic acid. In this way lower molecularweight polyoxyalkylene glycols can be employed without reducing thehydrophilic character of the resulting ester and emulsifiability ifcomparable or superior to compositions containing much largerproportions of the hydrophilic moiety. Also by the use of low molecularweight polyoxyalkylene glycols, the weight percent of the dimer acidpresent in the resulting ester mixture may be proportionately increasedwith the result that the lubricity of the ester compositions is markedlyenhanced. Thus, the present ester lubricant compositions provide theproper balance of dimer (which contributes to the lubricity) andpolyoxyalkylene glycol (which contributes to the emulsifiability) sothat exceptionally useful products are obtained. When very highmolecular weight polyoxyalkylene glycols are reacted with dimer acid inthe absence of a short-chain dibasic acid the lubrication properties ofthe resulting ester products are imparied. Similarly, when very lowmolecular weight polyoxyalkylene glycols are employed theemulsifiability is poor and the product unacceptable.

While the ability of the present invention to provide ester compositionshaving excellent lubricating and emulsifying properties is in itselfvery useful, a preferred embodiment of this invention is even moreadvantageous since it provides completely water-soluble esterlubricants. The water solutions are clear and homogeneous in allproportions. To obtain the water-soluble ester compositions thelubricant ester will contain from about 7.5 to about 20% by weight ofthe short-chain dibasic acid and have an acid value of about 15 orbelow. Acid values above about 15 are unacceptable if clear solutionsare to be obtained. It is unexpected that as the acid value of the estercomposition is decreased the water solubility or hydrophilic characterof the esters is increased. The solutions produced in accordance withthis preferred embodiment are stable and do not discolor or becomecloudy upon standing. The esters have excellent lubricity in addition tobeing completely water-soluble and may be successfully used in variousmetal working operations and as fiber finishes.

The lubricants of this invention are useful for working metals asaqueous emulsions or as the clear aqueous solutions. The concentrationof the ester for this purpose will generally range from about 0.1 toabout 25% by weight of the emulsion or solution although these estersmix with water in all proportions. The lubricant formulation may beadded to the metal-working elements or the metal itself by spraying orwith other similar equipment and form a uniform continuous film betweenthe rolls and the metal, thereby reducing friction and heat buildup.These lubricants are useful for working both ferrous and nonferrousmetals and they may be formulated with other additives such asstabilizers, corrosion inhibitors and the like depending on the end-useapplication.

The present ester compositions are also useful as an overfinish forpolymeric fibers derived from materials such as polyolefins, polyamides,polyacrylonitriles and polyesters. Such finishes are required during theprocessing of the fibers into yarns and fabrics to increase the surfacelubricity thereby reducing fiber-fiber friction and friction between thefiber and guides, draw pins, etc., of the processing equipment. Use ofthese finishing agents minimizes damage to the fibers, decrease filamentbreakage and facilitate the various processing steps. The estercompositions of this invention also reduce static charge buildup in thefibers during the processing. The esters of this invention areespecially useful with polyesters and polyamides and they significantlyimprove the lubricity of the fibers and improve the resistance to staticelectrical charge buildup.

Polyesters for which the present compounds, particularly the poly(ethylene glycol) dimerates, are useful include any of the condensationpolymers obtained when one or more diols are reacted with one or moredibasic acids or suitable derivatives thereof. They are also useful withcopolyesters and modified copolyesters. Glycols from which usefulpolyesters are obtained generally have the formula

    HO ( CH.sub.2 --.sub.n OH

wherein n is an integer from about 2 to 10. Such glycols includeethylene glycol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol,1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and thelike. Dicarboxylic acids typically employed include terephthalic acid,isophthalic acid, adipic acid, sebacic acid, succinic acid, oxalic acid,glutaric acid, pimelic acid, suberic acid, azelaic acid, and the like.In addition to these more common diols and dicarboxylic acids otheruseful reactants might include glycerol, sorbitol, pentaerythritol,methoxypolyethylene glycol, neopentyl glycol monohydroxypivalate,trimethylol propane, trimesic acid, p,p'-dicarboxydiphenylmethane,p,p'dicarboxydiphenoxyethane, p-carboxyphenoxy acetic acid and the like.Especially useful polyesters for the purpose of the present inventionare poly(ethylene terephthalate) and poly(1,4-cyclohexylenedimethyleneterephthalate) because of their commercial availability and superiorfiber-forming characteristics.

The present compositions are also useful as spin finishes to lubricateand provide protection against static charge buildup with polyamidesformed by the reaction of dicarboxylic acids, such as described abovefor the preparation of polyesters, and a diamine or suitable derivativethereof. Diamines which may be employed have the general formula

    H.sub.2 N ( CH.sub.2 --.sub.n NH.sub.2

wherein n is an integer from about 2 to 10, such as ethylenediamine,propylenediamine, tetramethylenediamine, pentamethylenediamine,hexamethylenediamine, decamethylenediamine and the like. Nylon-6 andnylon-6,6, are especially useful for the present invention. Polyamidesderived from the reaction of certain amino acids such as 6-aminocaproicacid, 7-aminoheptanoic acid, or the lactams of these acids, may also betreated in accordance with the present invention.

In general, the esters of this invention may be employed with anypolymeric material as a lubricant and to obtain improved resistivity tostatic electrical charge buildup. The emulsions or solutions of theesters can be applied to the polymer powder, on the surface of formedobjects such as pellets, rods, fibers, filaments, yarns, etc. Whenemployed as a fiber finish the concentration of the ester and the pickupare controlled to give the final weight of ester desired for acceptableprocessing. Finishes are typically applied to the fiber by passing thefiber through a bath or over a saturated roll containing the emulsion orsolution or by directly spraying the fiber. The esters may be added topolyesters, polyamides or other fiber-forming polymers by themselves orin combination with the other additives such as stabilizers,plasticizers, additional lubricants and antistatic agents and the like.

The esters may be incorporated into the polyester, polyamide or otherpolymeric material using conventional mixing equipment. They may beadded directly to the polymerizer while the polymer is being formed orreacted with a suitable prepolymer. The addition may be made at anystage of the polymerization, in toto, incremently or by proportioning,the manner and mode of addition being governed by the relativereactivities of the reactants and reaction conditions employed. Usingthis technique the ester becomes an integral part of the polymerstructure and consequently imparts some permanence to the lubricant andantistatic properties. The amount of ester reacted into the polymer willvary depending on the number of reactive groups available on the ester.As will be recognized by the person skilled in the art, numerousvariations are possible depending on the particular end-use applicationand are within the scope of the present invention. Irrespective of themethod of treating the polymer with the ester to obtain the propertiesheretofore described, the ester will constitute from about 0.1 to 10%,and more preferably from 0.2 to 2.5% by weight, of the polymercomposition.

The following examples illustrate this invention more fully, however,the examples are not intended to limit the scope of the invention. Allparts and percentages in the examples are given on a weight basis unlessotherwise stated.

EXAMPLE I

To a glass reactor equipped with a stirrer, thermometer and water trapwere charged 1030 grams (0.9 equivalent ratio) of dimer acid (Empol 1018containing 83% C₃₆ dibasic acid), 37.6 grams (0.1 equivalent ratio)azelaic acid and 1600 grams (2.0 equivalents) polyethylene glycol havingan average molecular weight of 400. The reaction mixture was heated withstirring to about 200°C and held for approximately 4 hours during whichtime 51 mls of water were removed. A vacuum of about 1 torr was pulledon the system to remove additional water of reaction. After one hour thereaction mixture was sampled and had an acid value of about 15.5.Heating was continued under vacuum for four more hours before thereaction mixture was cooled and poured up. The resulting lubricant estercomposition had a final acid value of 6.7, hydroxyl value of 93.1,viscosities (ASTM D 445-65) at 100°F and 210°F of 548 cs and 70.4 cs,respectively, and flash and fire points (ASTM D 92-66) of 555°F and605°F, respectively.

A portion (20 mls) of the ester composition was poured into 100 mls ofcold tap water while stirring with a glass rod. An emulsion wasimmediately obtained. This emulsion was stable and showed no signs ofphase separation after standing 48 hours at room temperature. Even aftera week's time the emulsion appeared homogeneous. A sample preparedidentically but with the azelaic acid excluded from the mixture was onlydifficulty emulsifiable. To obtain an emulsion required vigorousagitation with a mechanical stirrer. When this emulsion was allowed tostand at room temperature there was appreciable phase separation afteronly 24 hours with significant amounts of the oil settling to the bottomof the beaker.

To demonstrate the effectiveness of the ester compositions of thisinvention as lubricants they were evaluated with a Falex machine. Thismachine provides a convenient and reliable means to determine the filmstrength or load-carrying properties of materials as extreme pressuresare applied. Falex testing is recognized throughout the industry as ameans of masuring the relative effectiveness of various lubricants. TheFalex wear test (ASTM D 2670-67) employs a 60 gram sample when thestraight ester is being evaluated. A 600 gram sample is used whenaqueous emulsions or solutions of the ester are to be tested. Theloading device is attached and the cup containing the sample beingevaluated positioned so that the steel pin and blocks are completelyimmersed in the sample. The load is then increased to 350 lbs and runfor 5 minutes. After this time the load is further increased to 1000 lbsand maintained for 30 minutes when testing straight oils or one hourwhen evaluating lubricant emulsions or solutions. Readings are taken atthe beginning of the hour, after thirty minutes, and at the end of thehour and the difference in the readings indicates the amount of wear.

Three samples of the lubricant ester composition of this example wereevaluated in accordance with the described test procedure. The straightoil was evaluated and also 10% and 5% aqueous emulsions were tested.Test resuls obtained are as follows:SAMPLE UNITSWEAR______________________________________Straight ester: after 30minutes 18 after 60 minutes 3010% aqueous emulsion: after 30 minutes 1545% aqueous emulsion: after 30 minutes174______________________________________

When the above experiment was repeated employing a polyethylene glycolhaving an average molecular weight of about 800 similar results wereobtained. The ester compositions were readily emulsifiable and theemulsions had excellent stability. A 4% aqueous emulsion of this esterexhibited superior lubricating properties in the Falex test andperformed acceptably as a cutting oil with cold steel.

EXAMPLE II

Employing identical reactants and a similar procedure to that describedin Example I, 715 grams (0.5 equivalent ratio) dimer acid, 235 grams(0.5 equivalent ratio) azelaic acid and 2000 grams (2.0 equivalentsratio) polyethylene glycol were heated at 200°C for 6 hours during whichtime 55 mls of water were removed. An additional 10 mls of water wastaken off after pulling a vacuum on the system for one hour. The esterreaction mixture at this stage had an acid value of 19.8 and readilyformed an emulsion with water. Additional heating of the reactionmixture for 2 hours under vacuum reduced the acid value to 12.1. Theester (containing about 8 weight percent azelaic acid) had a hydroxylvalue of 105; viscosity at 100°F of 316 cs, viscosity at 200°F of 36.6cs, and flash and fire points of 530° and 585°F, respectively. The esterreadily dissolved in water in all propertions. No cloudiness wasobserved -- the resulting solutions were clear and homogeneous.

Falex wear tests gave the following results:

    SAMPLE                   UNITS WEAR                                           ______________________________________                                        Straight ester: after 30 minutes                                                                       30                                                           after 60 minutes 67                                                   10% water solution: after 30 minutes                                                                   132                                                   5% water solution: after 30 minutes                                                                   146                                                  ______________________________________                                    

EXAMPLE III

A water-soluble ester lubricant containing about 8% by weight adipicacid was obtained from the reaction of 0.4 equivalent dimer acid (83%C₃₆ dibasic acid), 0.6 equivalent adipic acid and 2.0 equivalentspolyethylene glycol having a molecular weight of 400. The reaction wascontinued until an acid value of 10.3 as achieved. The resulting estercomposition had a viscosity of 163 cs at 100°F. The ester lubricantmixed with water in all proportions to give clear solutions. Watersolutions containing 10% and 5% of the so-prepared ester were evaluatedin the Falex test machine and showed only 132 and 156 units of wear,respectively, after 30 minutes testing at 1000 psi.

Repeating the above example using 0.5 equivalent dimer acid and 0.5equivalent adipic acid and running the reaction to an acid value of 12.9gave useful ester lubricants. These compositions when mixed with waterdid not give clear solutions but did form stable emulsions without theuse of external emulsifying aids. The emulsions had excellent shelflives and were effective lubricants.

EXAMPLE IV

When Example I was repeated using 0.7 equivalent dimer acid, 0.3equivalent azelaic acid and 2.0 equivalents polyethylene glycol, auseful ester lubricant composition having an acid value of 9.1 wasobtained. The ester had a viscosity of 425 cs at 100°F and was readilyemulsifiable in cold tap water with minimal stirring and withoutaddition of external emulsifying aids. The emulsion so-produced hadexcellent shelf life and was an efficient lubricant. A 5% aqueousemulsion of this ester gave less than 150 units wear in the Falexmachine after 30 minutes at 1,000 psi.

Ester lubricant compositions were also prepared which incorporated up to0.2 equivalent of an amine corrosion inhibitor such as diethanolamine ordimethylaminepropylamine. The presence of these amines significantlyimproved the corrosion properties of the lubricant composition withoutadversely affecting the emulsion and lubrication characteristics. Insome instances the amines enhance the emulsion properties of the estercomposition even at reduced polyethylene glycol levels.

EXAMPLE V

Example I was repeated using 0.8 equivalent dimer acid, 0.2 equivalentazelaic acid and 2 equivalents polyethylene glycol. The lubricant ester(acid value 15.5) was easily emulsified. Stable emulsions were obtainedwhich were useful cutting oils when used with a tungsten carbide bit.

EXAMPLE VI

To demonstrate the ability of the present esters to function asfiber/metal lubricants and improve the resistance of the so-lubricatedfibers to static charge buildup several of the ester products wereapplied as finishes to polyester yarn and compared against acommercially available product used by the industry as a component fortextile finishes. Three samples (A-C) were prepared and applied at 0.5%o.w.f. on 150 denier polyester yarn which had been solvent-stripped toremove any finish applied by the producer. Samples A and B contained theesters of Examples I and II, respectively, while Sample C was preparedwith Emerest 2650 a product of Emery Industries, Inc., identified aspolyethylene glycol 400 monolaurate. The finishes were all applied fromaqueous systems with an Atlab Finish Applicator and the treated fibersthen conditioned for 24 hours at 70°F and 65% relative humidity prior totesting. Frictional properties were measured with a Rothschild F-Meterwith the initial tension held constant at 10 grams, a yarn speed of 100M/minute and yarn/metal contact angle of 180°. Test results are reportedbelow. Antistatic properties were also determined by insulating one ofthe pulleys on the F-meter and connecting it to a voltmeter andmeasuring the static charge produced on the pulley after an 8-secondinterval. The voltage "buildup" is reported in the table below. A staticmeasurement for antistatic properties was made by placing a 100 voltcharge on a strand of the yarn connected to a ground and determining thetime required for the charge to dissipate to 50 volts. This data isreported in the table below under the columm headed "Bleed-off."

    ______________________________________                                        Sample t.sub.2 (g)                                                                           f       Buildup (V)                                                                             Bleed-off (Sec)                              ______________________________________                                        A      37      0.39    500       30                                           B      30      0.32    350       10                                           C      22      0.22    625       12                                           ______________________________________                                    

The above data demonstrates the ability of the esters of this inventionto reduce fiber/metal friction and to impart antistatic properties topolyester yarns treated therewith. The antistatic properties obtainedwere superior in both the static and dynamic testing to propertiesobtaind with the commercial product. Reduction of friction comparedfavorably with the commercial product.

EXAMPLE VII

Single strand nylon (Dupont 15847) was immersed in 0.5% wateremulsion/solution of the following:

    Sample          Additive                                                      ______________________________________                                        A               Product of Example I                                          B               Product of Example II                                         ______________________________________                                    

The fibers were then conditioned at 68°F and 40% relative humidity andtested using the static bleed-off test. Results were as follows:

    Fiber treated with Minutes to 50% Bleed-off                                   ______________________________________                                        A                  11.08                                                      B                  7.76                                                       ______________________________________                                    

A fiber which was not treated with either of the above solutions showedno dissipation of charge even after 10 minutes.

We claim:
 1. The method for lubricating and improving antistaticproperties of polymeric materials which comprises treating a polymericfiber selected from the group consisting of polyolefins, polyamides,polyacrylonitriles and polyesters with an ester obtained by reactingabout 1.5 to 2.1 mols polyoxyalkylene glycols having a molecular weightfrom about 300 to 4000 wherein the recurring alkylene groups containfrom 2 to 4 carbon atoms with 1 mol of a mixture of dibasic acidsconsisting of 5 to 95 mol percent dimer acids containing 32 to 54 carbonatoms and 95 to 5 mol percent short-chain dibasic acids containing 2 to12 carbon atoms, so that about 70% or more of the carboxyl groups arereacted.
 2. The method of claim 1 wherein the polyoxyalkylene glycol isa polyethylene glycol of molecular weight 400 to 1000 and theshort-chain dibasic acid contains 6 to 10 carbon atoms and constitutesfrom 20 to 90 mol percent of the dibasic acid mixture.
 3. The method ofclaim 2 wherein the mol ratio of the dibasic acids to polyoxyalkyleneglycol is 1:1.75-2.0 and greater than 85% of the carboxyl groups of thedibasic acid are reacted.
 4. The method of claim 3 wherein the acidvalue of the ester is 15 or below and the short-chain dibasic acidcomprises from about 7.5 to 20 weight percent of the ester composition.5. The method of claim 1 wherein the polymeric fiber is treated with anaqueous composition containing from about 0.1 to 25% by weight of theester derived from the reaction of 1.75-2.0 mols polyethylene glycol ofmolecular weight 400 to 1000 with one mole of a mixture of dibasic acidsconsisting of short-chain dibasic acids containing 6 to 10 carbon atomsand dimer acid containing at least 75% by weight C₃₆ dibasic acids, saidacids having greater than 85% of the carboxyl groups reacted.
 6. Themethod of claim 5 wherein the ester contains from about 7.5 to 20 weightpercent short-chain dibasic acid and has an acid value of 15 or below.7. The method of claim 6 wherein the short-chain dibasic acid is azelaicacid.
 8. The method of claim 5 wherein the polymeric fiber ispoly(ethylene terephthalate) or poly(1,4-cyclohexylenedimethyleneterephthalate).
 9. The method of claim 5 wherein the polymeric fiber isnylon-6 or nylon-6,6.